People who have multiple autoantibodies targeting their pancreatic islets, but still maintain normal blood sugar levels, show a smaller insulin response to oral glucose compared to intravenous...

People who have multiple autoantibodies targeting their pancreatic islets but still have normal blood sugar levels show a 45% decrease in the hormone response that helps regulate insulin after eating, along with lower levels of the GIP hormone during a glucose test, indicating early metabolic changes before diabetes develops.

In people who have antibodies indicating early risk for type 1 diabetes but still have normal blood sugar, a decrease in the hormone GIP—compared to GLP-1—appears to be the main reason for reduced insulin response after eating, which may make GIP a better early indicator of pancreatic beta-cell stress.

In female mice, when the receptors for two specific gut hormones (GIP and GLP-1) are removed, the body no longer releases extra insulin after eating glucose compared to receiving it directly into the bloodstream, even when blood sugar levels are the same. This suggests these two hormones are responsible for the increased insulin response seen after eating.

In female mice, removing the receptors for two gut hormones (GIP and GLP-1) prevents the normal increase in insulin production after eating glucose, reducing the insulin response by about 65% compared to normal mice, showing that these two hormones are responsible for most of the insulin boost triggered by oral glucose in this model.